Electron cooling for the Fermilab recycler

In all scenarios of the possible Tevatron upgrades, luminosity is essentially proportional to the number of antiprotons. Thus, a tenfold increase in luminosity could be achieved by putting five times more protons on the antiproton production target and gaining an additional factor of two from recycling antiprotons left over from the previous store. Stacking and storing ten times more antiprotons puts an unbearable burden on the stochastic cooling system of the existing accumulator ring. Thus, one is led to consider an additional stage of antiproton storage, the so called recycler ring. Electron cooling of the 8 GeV antiprotons in the recycler could provide an attractive way around the problems of large stacks. Such a system would look much like the IUCF proposal to cool 12 GeV protons in the SSC medium energy booster [1]. Although electron cooling has now become a routine tool in many laboratories, its use has been restricted to lower energy accelerators (<500 MeV/nucleon). An R&D program is currently under way at Fermilab to extend electron cooling technology to the GeV range. This paper describes the electron cooling system design as well as the recycler ring parameters required to accommodate this system.